/*
 * Created on 21-Jun-2004
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package org.gudy.azureus2.core3.internat;

/**
 * @author parg
 *
 */

import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.util.Arrays;

import org.gudy.azureus2.core3.util.Constants;
import org.gudy.azureus2.core3.util.Debug;

public class LocaleUtilDecoderReal implements LocaleUtilDecoder {
    protected CharsetDecoder decoder;
    protected int index;

    protected LocaleUtilDecoderReal(int _index, CharsetDecoder _decoder) {
        index = _index;
        decoder = _decoder;
    }

    public String getName() {
        return (decoder.charset().name());
    }

    public int getIndex() {
        return (index);
    }

    public String tryDecode(byte[] array, boolean lax) {
        try {
            ByteBuffer bb = ByteBuffer.wrap(array);

            CharBuffer cb = CharBuffer.allocate(array.length);

            CoderResult cr = decoder.decode(bb, cb, true);

            if (!cr.isError()) {

                cb.flip();

                String str = cb.toString();

                // lax means that as long as the conversion works we consider it usable
                // as opposed to strict which requires reverse-conversion equivalence

                if (lax) {

                    return (str);
                }

                byte[] b2 = str.getBytes(getName());

                // make sure the conversion is symetric (there are cases where it appears
                // to work but in fact converting back to bytes leads to a different
                // result

                /*
                 * for (int k=0;k<str.length();k++){ System.out.print( Integer.toHexString(str.charAt(k))); } System.out.println("");
                 */

                if (Arrays.equals(array, b2)) {

                    return (str);
                }
            }

            return (null);

        } catch (Throwable e) {

            // Throwable here as we can get "classdefnotfound" + others if the decoder
            // isn't available

            return (null);
        }
    }

    public String decodeString(byte[] bytes)

    throws UnsupportedEncodingException {
        if (bytes == null) {

            return (null);
        }

        try {
            ByteBuffer bb = ByteBuffer.wrap(bytes);

            CharBuffer cb = CharBuffer.allocate(bytes.length);

            CoderResult cr = decoder.decode(bb, cb, true);

            if (!cr.isError()) {

                cb.flip();

                String str = cb.toString();

                byte[] b2 = str.getBytes(decoder.charset().name());

                // make sure the conversion is symetric (there are cases where it appears
                // to work but in fact converting back to bytes leads to a different
                // result

                /*
                 * for (int k=0;k<str.length();k++){ System.out.print( Integer.toHexString(str.charAt(k))); } System.out.println("");
                 */

                if (Arrays.equals(bytes, b2)) {

                    return (str);
                }
            }
        } catch (Throwable e) {

            // Throwable here as we can get "classdefnotfound" + others if the decoder
            // isn't available

            // ignore
        }

        try {

            // no joy, default

            return (new String(bytes, Constants.DEFAULT_ENCODING));

        } catch (UnsupportedEncodingException e) {

            Debug.printStackTrace(e);

            return (new String(bytes));
        }
    }
}
